Assertion : Bats and whales are classified as mammals.

Reason : Bats and whales have four-chambered heart.

• If both Assertion and Reason are true and the reason is the correct explanation of the assertion

• If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

B.

If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

Bats and whales are classified as mammals as they possess the essential mammalian characteristics like presence of milk gland or mammae, presence of pinnae, viviparous nature, hair on body, presence of diaphragm etc.

Though bats and whales have four chambered heart, it cannot be considered as the main characteristic of being mammals because it is also present in some reptiles (e.g. crocodile) and all birds.